High speed low noise current collecting equipment and method on collecting current

ABSTRACT

A low noise current collector 20 having excellent controllability and response, and a high speed railway train using such current collectors. The current collector 20 includes an aerodynamically shaped current collector head 22, a driving cylinder 32 to move the current collecting head, a supporting insulator 30, and a cable head 50 supporting a conductor 53 for conducting current from current collecting head 22 to a load. The current collector 20 is controlled by a cylinder 7 for raising and lowering so that the current collector may be contained in a dome 4 when it is in use. A multi-car train has four current collectors, two toward each end, and each current collector has its front side directed toward the center of the train. The two current collectors at the rear of the train are utilized, while the two at the front are contained within their domes 4. Therefore, the train can run in either direction, utilizing the appropriate pair of current collectors.

This application is a Division of application Ser. No. 08/174,280, filedDec. 28, 1993.

BACKGROUND OF THE INVENTION

The present invention relates to current collecting equipment and amethod of current collecting for a railway vehicle, such as a high speedrailway vehicle.

Aerodynamic noise which is produced by a high speed railway vehiclerapidly increases with increasing speed of the vehicle proportional toapproximately the eighth power of its velocity. On the other hand, theconcern about preservation of the environment has been growing and willbe an important factor in the future. Therefore, it is required for avehicle running at a high speed (for example, over 270 km/hr) to carrylow noise current collecting equipment.

A low noise current collecting equipment is proposed in an articleentitled "Speeding up SHINKANSEN" (Nikkei mechanical, published on May4, 1992, pages 22 to 40). The following is described in this report(especially on page 27).

It is desirable for lowering noise that a member having a contact stripas a current collecting member has a streamlined shape. Taking thecombination of the streamline-shaped member and strut supporting themember into consideration, a lifting force takes place. The lift causesthe contact strip to become detached from the trolley wire or contactsto the trolley wire with exceeding force to cut the trolley wire. Withthe provision of two kinds of current collecting equipment depending onthe direction of running of the vehicle, switching from the one kind tothe other kind is performed at a turn back station. The currentcollecting equipment is T-shaped and is formed with large sized membersin order to decrease any produced frequency vibration.

Further, taking these facts described above into consideration, a viewof a T-shaped current collecting equipment is illustrated in FIG. 5 inthe paper. This current collecting equipment comprises a membersupporting a contact strip with a fine motion spring, a cylinder forraising and lowering the member through a restoring spring, and aninsulator supporting the cylinder.

On the other hand, the conventional pantograph type current collectingequipment comprises a pantograph having a contact strip, a pneumaticcylinder for raising and lowering the pantograph, four insulators tosupport and insulate a support base mounting the pantograph and thepneumatic cylinder, and a conducting cable installed on the roof of thevehicle. The compressed air supply to the pneumatic cylinder isperformed with an installed pipe penetrating through the insulator.

Further, other constructions of current collecting equipment for highspeed railway vehicles in order to lower noise are also described inJapanese Patent Application Laid-Open No. 5-49103(1993) and JapanesePatent Application Laid-Open No. 5-49104(1993).

The current collecting equipment for high speed railway vehicles, theT-shaped current collecting equipment proposed in the above paper andthe current collecting equipment for high speed railway vehiclesproposed in the above Japanese Laid-Open Patent ApplicationApplications, are designed to resolve the problems which accompany highspeed running. However, since the functions of the pantograph, (1) thefunction of contacting and following a trolley wire and (2) the functionof conducting current to direct collected electric power to the vehicle,are attempted to be provided with only one construction, as in theconventional pantograph, it is difficult to satisfy the seeminglyconflicting requirements concerning responsive following of the trolleywire and lowering of noise caused by increasing the vehicle speed.

For example, the conventional T-shaped current collecting equipment hasthe following disadvantages. First, the cylinder for raising andlowering the contact is positioned on the contact strip side near tothe-supporting insulator. Therefore, said cylinder for raising andlowering has to be provided as a pneumatic cylinder. Although it isdesirable for a high speed vehicle, from the point of view of responsivecontrol, to employ an oil-hydraulic cylinder, the oil-hydraulic cylindercannot be employed in the equipment.

Further, the raising and lowering cylinder has a control system tomaintain the contact pressure against the trolley wire constant andrequires means for detecting the contact pressure, such as a load cell,to be used as a control input. The position to set the contact pressuredetecting means is on the contact strip side near the raising andlowering cylinder. Since the position is in a portion of the highvoltage region, the countermeasure for insulation of the detecting meansis required.

Furthermore, although the current collecting equipment is designed forcollecting current, the above-mentioned paper does not disclose itscurrent conducting system at all.

With regard to the cylinder that is used to raise or lower the currentcollecting equipment when it is switched at a turn back station, sincethe current collecting equipment not being used forms a projection,there is a limit to the lowering of noise produced by the equipment.

It is thought that the current collecting equipment described in theabove-mentioned Japanese Laid-Open Patent Applications also have thesame problem.

SUMMARY OF THE INVENTION

An object of the present invention is to provide current collectingequipment and a method for current collecting suitable for a high speedrailway vehicle which is excellent in its controllability and inresponsiveness for trolley wire following.

Another object of the present invention is to provide current collectingequipment and a method for current collecting suitable for a high speedrailway vehicle which is low in producing noise.

A further object of the present invention is to provide currentcollecting equipment and a method for current collecting which iscapable of preventing production of noise caused by the currentcollecting equipment not being used.

A still further object of the present invention is to provide a vehiclehaving current collecting equipment which is always capable of correctlycontrolling the contact pressure against the trolley wire during highspeed running.

The objects of the present invention can be attained by separating thefunctions of a pantograph into a function of following the trolley wireand a current conducting function for collected electric power in orderto make the current collecting equipment carry out each of thefunctions. In other words, the object of the present invention can beattained by providing current collecting equipment which comprises acurrent collecting member, a driving system to move said currentcollecting member, an insulating element to connect said currentcollecting member and said driving system, a conductive elementjuxtaposed with said driving system and having its outer surface coveredwith an insulator to receive the current collected with said currentcollecting member and to direct the current to the load side.

The objects of the present invention can also be attained by providingcurrent collecting equipment which comprises a current collectingmember, a driving system to move said current collecting member, aconductive element to direct the current collected with said currentcollecting member, a support base mounting said driving system and saidconductive element, rotating means for rotating said support base arounda horizontal axis, a containing part mounted on the roof of the vehicleto contain said rotating means and containing said driving system andsaid current collecting system.

According to the present invention, a part of the structure having acurrent collecting function can be light in weight and small in size andcan improve the control characteristic for the following of the trolleywire, since the part of the structure having the current collectingfunction, which comprises the current collecting member and the drivingsystem, is installed separately from a part of the structure having thepower current conducting function, which can, further, maintain thepower current collecting function sufficiently.

Furthermore, the generation of noise during vehicle running can besuppressed since there is provided a containing system on the roof ofthe vehicle inside of which the driving system is always contained andthe part of the structure having the current collecting functiontogether with the part of the structure having the power currentconducting function is contained when it is not used

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view showing the external appearance of a high speedvehicle to which the present invention is applied.

FIG. 2 is perspective view of the vehicle in FIG. 1 when the currentcollecting equipment is in a current collecting condition.

FIG. 3 is a plan view of current collecting equipment and a containingdome forming an embodiment according to the present invention.

FIG. 4 is a vertical sectional view of current collecting equipment anda containing dome according to the present invention.

FIG. 5 is a transverse view taken on the plane of the line I--I in FIG.4.

FIG. 6 is a vertical sectional view of the main part-of the currentcollecting equipment in FIG. 3.

FIG. 7 is a side view showing the driving system of the currentcollecting equipment in FIG. 3.

FIG. 8 is a plan view of the current collecting equipment in FIG. 6.

FIG. 9 is a front view of the current collecting equipment in FIG. 6.

FIG. 10 is a sectional view of the current collecting equipment taken onthe plane of the line II--II in FIG. 6.

FIG. 11 is a sectional View of the current collecting equipment taken onthe plane of the line III--III in FIG. 10.

FIG. 12 is a sectional view of the current collecting equipment taken onthe plane of the line IV--IV in FIG. 10.

FIG. 13 is a plan view showing the operation of a shutter system in acontaining dome.

FIG. 14 is a plan view showing the operation of a shutter system in acontaining dome.

FIG. 15 is a vertical sectional view showing the main part of a shuttersystem.

FIG. 16 is a vertical sectional view showing the main part of anothershutter system.

FIG. 17 is a enlarged side view of a containing dome.

FIG. 18 is a view for explaining the operation of extending currentcollecting equipment from a containing dome.

FIG. 19 is a view for explaining the operation of housing currentcollecting equipment in a containing dome.

FIG. 20 is a perspective view of the external appearance showing thecondition of housing current collecting equipment in a containing dome.

FIGS. 21(a) through 21(c) are horizontal sectional views of thesupporting insulator and the conductive element, and relationshipsbetween air flow and the configuration.

FIG. 22 is a vertical sectional view showing the positional relationshipbetween the current collecting member and the supporting insulator.

FIG. 23 is a schematic circuit diagram showing an example of theelectric wiring in a train of vehicles applied to the present invention.

FIG. 24 is a vertical sectional view of the high voltage unit box inFIG. 23.

FIG. 25 is a block diagram showing a structure of the control system inFIG. 23

FIG. 26 is a diagram showing the flow of a control command for thecurrent collecting equipment.

FIG. 27 is a flow diagram showing the operational procedure of apulling-down command for the current collecting equipment.

FIG. 28 is a flow diagram showing the operational procedure of a raisingcommand for the current collecting equipment.

FIG. 29 is a block diagram showing the structure of an oil-hydraulicdriving system for the current collecting equipment.

FIG. 30 is a block diagram showing the structure of a push-up forcecontrol system for the current collecting equipment.

FIG. 31 is a block diagram showing the structure of a current collectordriving system.

FIG. 32 is a block diagram showing the structure of a containing drivingsystem.

FIG. 33 is a vertical sectional view of current collecting equipmentforming another embodiment according to the present invention.

FIG. 34 is a view showing an example of the structure applied by thepresent invention to a current supplying system of a third rail type.

FIG. 35 is a plan view showing a further embodiment of currentcollecting equipment and a containing dome according to the presentinvention.

FIG. 36 is a view showing a cross section taken on the plane of the lineV--V in FIG. 35.

FIG. 37 is a view showing a cross section taken on the plane of the lineVI--VI in FIG. 35.

FIG. 38 is a view showing the contained condition of the currentcollecting equipment in FIG. 35.

FIG. 39 is a view showing current collecting equipment with an emergencyground switch.

FIG. 40 is a perspective view showing a current collector in accordancewith the present invention.

FIG. 41 is an illustrative view of the air flow around a currentcollector in accordance with the present invention.

FIG. 42 is an illustrative view of air flow around a conventionalstream-lined current collector.

FIG. 43(a) is a diagram of a collector head and FIG. 43(b) is a graphshowing the pressure distribution in the lateral direction on thesurface of the collector head of current collecting equipment inaccordance with the present invention.

FIG. 44(a) is a diagram of a collector head and FIG. 44(b) is a graphshowing the pressure distribution in the lateral direction on thesurface of the collector head of a conventional stream-lined currentcollecting equipment.

FIG. 45 is a view showing the shape of a low aerodynamic noise collectorhead and supporting column in accordance with the present invention.

FIG. 46 is a graph showing the results of a wind tunnel test showing thenoise decreasing effect of current collecting equipment in accordancewith the present invention.

FIG. 47 is a perspective view showing another current. collector inaccordance with the present invention.

FIG. 48 is a cross-sectional view showing another current collector inaccordance with the present invention.

FIG. 49 is a perspective view showing another current collector inaccordance with the present invention.

FIG. 50 is a view showing another current collector in accordance withthe present invention.

FIG. 51 is a graph showing the results of a wind tunnel test showing theeffect of the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment according to the present invention will be describedin detail, referring to FIG. 1 through FIG. 32.

FIG. 1 shows an external appearance of a high speed vehicle to which thepresent invention is applied. In order to lower noise, the externalsurface of a vehicle body 2 is formed smooth, and bogies are alsocovered with covers 2C. The bottom half of a current collector 20 ispositioned so as to be surrounded by a containing dome 4. The main partsof current collecting system, such as a supporting insulator forinsulation, a cable head for current conduction, a collector head and soon, are projected from the center of the containing dome 4 and intocontact with a trolley wire, when current is to be collected. Theexternal surface of the containing dome 4 is streamline-shaped to loweraero-dynamic resistance. Inside of the containing dome, there are a baseplate 3, a high voltage cable 5, a high voltage connector 6, and acylinder 7 coupled to a connecting rod 8 to raise and lower the currentcollector 20.

For such a vehicle, the voltage in the trolley wire is generally usedalternating current of 25 kV, the current is 200 A, and the cycle is50-60 Hz. In order to maintain a sufficient insulation distance and acreeping distance for such a high voltage, it is necessary to use a verytall current collector 20 and an insulator having a lot of folds. Suchan insulator produces a running aerodynamic resistance and becomes alarge noise source when the vehicle is running at a high speed.Therefore, the current collector 20 according to the present inventionis contained in the inside of the dome 4 when the apparatus is not in acurrent collecting condition.

FIG. 2 shows a condition where the current collector 20 is in thecurrent collecting condition and extends up near the center of thecontaining dome 4. The gap between the current collector 20 in thecurrent collecting condition and the containing dome 4, which forms theopening for the current collector, is entirely closed with a shuttersystem 9.

FIG. 3 through FIG. 7 show detailed views of the current collector 20and the containing dome 4 in accordance with the present invention.

Since the current collector 20 is not operated with a folding structure,as provided in the conventional pantograph, the current collector 20, asone unit of a collector head 22, a support insulator 30, a driving rod31 for upward and downward driving, a cylinder 32, a cable head forcurrent conduction 50, is rotated with a rotating system 40 around ahorizontal axis so as to be lowered into the containing dome 4 when itis not in the current collecting condition. Therewith, the aero-dynamicresistance and the noise during vehicle running can be decreased.

Raising and lowering of the current collector 20 is performed with acylinder 7 and a rod 8 to rotate the current collector 20 around an axis40A of the rotating system 40. Incidentally, the rotating system 40 issupported with a fixed member 41 which is mounted on the base plate 3 ona car body 2.

When the current collector 20 is raised or lowered, the shutter system 9is opened with operation of a cylinder 42 and a rod 43. When the currentcollector 20 is collecting current or is contained in the containingdome 4, the shutter system 9 is closed. These operations are carried outby the control of a sequencer or a computer installed separately. Thedetails of this will be described later.

A high voltage flexible cable 44 is subject to heavy fatigue and isrequired to be changed on schedule since it is moved every time thecurrent collector 20 is raised and lowered. Therefore, a high voltageconnector 6 is provided between the flexible cable 44 and the highvoltage cable 5 buried in the car body 2 so as to make changing of thehigh voltage flexible cable 44 easy.

Any water which enters into the containing dome 4 from the gaps betweenshutters 110, 120, 130, 140 or the gaps between the insulator 30, or theinsulating member 50 and the shutter 130, flows out to the roof of thevehicle through drain holes 46 provided on both side walls in the bottomof the containing dome 4. As the roof of the vehicle body 2 is, as shownin FIG. 5, arc-shaped in a convex upward orientation, draining is easilycarried out through the drain holes 46 on both side walls of thecontaining dome 4.

As shown in FIG. 6 through FIG. 9, contact strips 21 for currentcollecting are buried on the top of the collector head 22 having adelta-wing shape, and are pushed against the trolley wire 1 by contactstrip pressing springs 23 and with a driving system which will bedescribed later. The collector head 22 is secured to the top of thesupporting insulator 30 with bolts, and the supporting insulator 30 issecured to a driving rod 31 positioned below and projecting from adriving cylinder 32. The numeral 33 designates a load cell to detect theforce acting between the driving rod 31 and the supporting insulator 30,that is the reaction force to push up the collector head 22. The drivingrod 31 is pushed up by means of hydraulic pressure produced with ahydraulic pressurizer separately installed in such a way that thecontact pressure of the current contact strips 21 against the trolleywire 1 is controlled to become optimum.

The collector head 22 has a nearly triangular wing shape when it is seenfrom above, as shown in FIG. 8. The ends in the width-direction of thecollector head 22 are bent in a downward direction. There are contactstrips 21a secured on the top surface of the wing in those portions.These contact strips are made of a harder material than the material ofthe wing (such as, for example, steel, copper, brass). These members aredummy strips to prevent the collector head 22 from abrasion when thetrolley wire comes to the wing end portion and the collector head 22itself contacts the trolley wire 1. The contact strips 21a are securedto the collector head 22 with bolts such that the strips have the samepotential as the collector head to prevent sparking. The bolts arepositioned in the hollow parts in the contact strips to decreaseprojecting parts on the surface. There is no spring 23 between thecontact strips 21a and the collector head 22.

The contact strips 21 and 21a are electrically connected to a conductingwire 51a. When the collector head 22 is made of a non-conductivematerial, such as FRP, a conductive member is provided between thecontact strips 21 and 21a and the conductive wire 51a.

The external surface of the connecting part of the supporting insulator30 and the collector head 22 is arc-shaped. Thereby, the production ofaerodynamic noise generated in said portion is decreased.

The longitudinal cross section of the collector head 22 is stream-lineshaped the height of which is progressively reduced in the rear-warddirection, as shown in FIG. 6. The material of the collector head 22 isaluminum in order to decrease its weight. It may be formed mainly withresin, the surface of which is coated with GFRP or CFRP.

The driving rod 31 for the driving cylinder 32 and the bottom portion ofthe supporting insulator 30 are connected through a unit of the loadcell 33 by way of the top and bottom flanges thereof. The bottom portionof the supporting insulator 30 is cylindrical, and the diameter of thesupporting insulator 30 is the same as the diameter of the cylinderportion of the cylinder 32. This portion is covered with a sleeve 59.The sleeve 59 is longitudinally cut into halves which are fixed to thecylindrical portion of the supporting insulator 30 and the cylinderportion of the cylinder 32 from outer-ward of the radial direction usingflat countersunk head screws. The length of the sleeve 59 is longer thanthe stroke of the driving rod 31. The corner of the top end of thesleeve 59 is rounded. The driving rod 31 is a rod driven withoil-hydraulic pressure. The numeral 130 indicates a shutter to cover thesurrounding area of the sleeve 59, which will be described later.

The cable head for current conduction 50 described above has a structurein which the conductive element 53 penetrates the center of theinsulator 52 in the axial direction. The top of the conductive element53 projects from the insulating portion, and has a brace projectingsideways which is fixed with bolts. Instead of this, a protective capmay be attached to the portion, as well known. A high voltage flexiblecable 44 is attached to the bottom end of the conductive element 53. Theouter diameter of the cable head 50 gradually decreases toward its top,and the cable head 50 serves as a high voltage insulator.

The brace on the top of the conductive element 53 and the collector head22 are connected with a conductive wire 51 which is flexibly braided.The conductive wire 51 is fixed with bolts and nuts and is formed of abraided wire, so that the collector head 22 may easily move upward anddownward relative to the cable head 50, and has at least one U-shapedturn in a part thereof. The U-shaped turn in the conductive wire 51makes upward and downward movement easy even when the distance betweenthe fixed ends of the conductive wire 51 is small. The cable head 50 ispositioned at the back of the supporting insulator 30, and theconnecting positions of the conductive wire 51 with the collector head22 and the conductive element 53 are also positioned at the back of thesupporting insulator 30.

The insulator in the cable head 50 has, as shown in FIG. 6, an unevenportion in its surface, and its bottom portion 52 is columnar. Thebottom of the column 52 is fixed to a base 55 from an upper side withbolts. The base 55 and the cylindrical portion of the cylinder 32 areformed as a single unit structure. As seen in FIG. 10 through FIG. 12,there is an opening (55a) in the side surface of the base 55 (the backside in the direction of running) so that the connection portion of thehigh voltage flexible cable 44 can be inserted from a side directioninto the bottom portion of the insulator 52. There are flanges in thebottom of the cable head 50 and in the top of the base 55 which areconnected together with a plurality of bolts.

There are connecting portions for the cylinders 7 for raising andlowering the collector head in both sides of the base 55 on either sideof the hollow space in the connecting portion of the cable head 50through which the high voltage flexible cable 44 is penetrated. Theextending direction of the cylinder 7 is in the longitudinal directionof the vehicle. The high voltage flexible cable 44 is positioned betweenthe two cylinders 7, as seen in FIG. 10. The high voltage flexible cable44 is connected to the cable 5 through the connector 6. The high voltageflexible cable 44 is softer than the cable 5. The connector 6 has such astructure that connecting and disconnecting of the connector 6 and thehigh voltage flexible cable 44 is comparatively easily carried out.

Now returning to FIG. 6 and FIG. 7, the parts, such as the drivingcylinder 32, the connector 6, the cylinder 7 and so on, are mounted onthe base plate 3 through the fixed member 41. The base plate 3 is fixedto a base secured to the roof of the vehicle itself with bolts. There isa cut part in the base plate 3 below the high voltage flexible cable 44to make room for bending of the high voltage flexible cable 44 and tomake bending of the high voltage flexible cable during rotation of thesupporting insulator 30 easy.

By employing this structure, the operation of the driving rod 31 doesnot affect the high voltage flexible cable 44. The driving rod 31 has afunction to push the current collecting contact strip 21 against thetrolley wire 1 with a desired pressure as it moves up and down withconsiderably high frequency. Although the high voltage flexible cable 44is bent with the operation of the cylinder 7 for raising and loweringthe collector head, the bending condition occurs substantially only atthe turn back operation and the frequency of bending is extremely small.Therefore, a long wearing life of the cable can be achieved. The loadcell 33 can detect the contact pressure with the trolley wire 1.

Since the supporting insulator 30 is disposed between the driving rod 31and the collector head 22, the driving rod 31 is not subjected to a highvoltage. Therefore, an oil-hydraulic type driving cylinder 32 can beemployed, which improves the responsiveness to the control signal.

Similarly, since the load cell 33 (pressure sensor) is also installed ina position where a high voltage is not applied, an accurate controlinput can be obtained.

Since the sleeve 59 is positioned at the bottom end of the supportinginsulator 30 and the gap between the supporting insulator 30 and thecontaining dome 4 can be made small, the inflow of rain, snow or airinto the sleeve 59 can be prevented even though the diameter of the rod31 at the bottom end of the support insulator is small. Therefore, thelength below the bottom end fold of the supporting insulator 30 can bemade small.

Incidentally, the sleeve 59 may be eliminated when the length of thecolumn at the bottom end of the supporting insulator 30 is longer thanthe stroke of the driving rod 31.

As shown in FIG. 13 and FIG. 14, there are shutters 110, 120, 130 and140 in the portion where the current collector 20 penetrates the dome 4,and the shutters usually close the opening. The shutter 110 is a shutterto close the opening through which the collector head 22 penetrates, andis formed of a piece of flat plate. The shutters 120, 120 are shuttersto cover the opening through which the supporting insulator 30penetrates, and are divided in the width-direction of the vehicle intotwo portions to close one opening with a pair of flap type shutters. Theshutters 130, 130 are sliding type shutters to cover the opening wherethe insulators 30 and 52 pass in the condition of raising upright, andare divided in the width-direction of the vehicle into two portions toclose one opening with a pair of shutters. When the shutters 130, 130close the opening, two circle holes are opened to be penetrated with thesleeve 59 and the insulators 30 and 52. The shutter 140 is a piece ofsliding type shutter to close the same opening that the shutters 140,140 close when the current collector 20 is contained in the containingdome 4. At this time, the shutters 130, 130 do not close the opening.

Referring to FIG. 14 though FIG. 16, the structure of the drivingmechanism of the shutter 110 will be described next. The shutter 110, asshown in FIG. 15, is of a

sliding type, and is slid along the longitudinal direction of thevehicle. There are guide rails 115 supporting both side ends of theshutter 110 in both sides of the opening 110a closed with the shutter110 in the width-direction of vehicle. Both sides of the shutter 110 aresupported with the guide rails 115 through four rollers 112. The guiderails 115 guide the top, bottom and side of the rollers 112. The shutter110 is positioned on the reverse side of the containing dome 4 when theopening is open, and is fitted in the opening when the opening isclosed. In other words, when the opening is closed, the upper surface ofthe shutter 110 is coextensive with the upper surface of the containingdome 4. The guide rails 115 have curves so as to move the shutter 110 asdescribed above. A cylinder 42 for up- and down-ward driving of theshutter 110 is installed on the base plate 3.

The shutters 120 are, as shown in FIG. 16, opened and closed by turningwith hinges 122 as turning axes. Cylinders 129 are installed on the baseplate 3.

The shutters 130 are of a sliding type similar to the shutter 110. Theguide rails 135 for the shutters 130 are not installed in the sideportion of the opening. The reason for this is to prevent crossing overwith the shutter 140. Therefore, the portion of the shutter to close theopening has no guide roller either. In order to put guide rollers on theshutter 130, the shutter 130 has such a shape that the shutter islargely extended toward the opposite side of the running direction whenthe opening is opened. Cylinders 139 are installed on the base plate 3.The other structure for the shutters 130 is the same as the structurefor the shutter 110.

In FIG. 15 and FIG. 16, there are provided heaters 47 and 48 in thecircumference of the shutters 110 and 120 of the containing dome 4. Aheater may be provided at the portion where the shutters 120 contacteach other, if necessary. The other shutters 130 and 140 also haveheaters (not shown). When the shutters tend to freeze in winter season,the shutters 110, 120, 130 and 140 are opened after the heaters aresupplied electric power to melt ice, and so the current collector 20 iseasily controlled through its raising and lowering movements.

The shutters 140 are of a sliding type similar to the shutter 110. Theguide rails 145 for the shutters 140 are not installed in the sideportion of the opening. The reason for this is to prevent crossing overwith the shutter 130. Therefore, the portion of the shutter to close theopening has no guide roller either. In order to put guide rollers on theshutter 140, the shutter 140 has such a shape that the shutter islargely extended toward the opposite side of the running direction whenthe opening is opened. Cylinders 149 are installed on the base plate 3.The other structure for the shutters 140 is the same as the structurefor the shutter 110.

The containing dome 4 is, as shown in FIG. 17, partitioned into threeparts 4A, 4B, 4C. The containing dome part 4A is the region from theguide rail 135 for the shutter 130 to the guide rail 115 for the shutter110. The containing dome 4 has inspection hatches 4Aa, 4Bb, 4Cc on theside surface of the containing dome in appropriate positions to be usedfor inspection, assembling and replacement of parts for the devices inthe containing dome 4.

The current collector 20 projecting upward from the containing dome 4is, as shown in FIG. 18 through FIG. 20, contained in the containingdome 4 by driving the cylinder 7. First, the collector head 22 isslightly pulled down (approximately 100 mm) to be detached from thetrolley wire 1, as shown in FIG. 18. Next, as shown in FIG. 19, theshutter 9 is opened, and the current collector 20 is lowered completelyinto the containing dome 4, and then finally the shutter 9 is closed.The condition where the current collector 20 is contained in thecontaining dome 4 is as shown in FIG. 15, all the openings being closedwith the shutter system 9, the external surface of the containing dome 4being of a sooth stream-lined shape, which hardly produces runningresistance or noise source during high speed running. The followingshows an example of the detailed dimensions of an embodiment accordingto the present invention.

    ______________________________________                                        height of containing dome                                                                           HD = 700 mm                                             total length of containing dome                                                                     L = 9300 mm                                             (hereinbefore referred to FIG. 4)                                             width of base of containing dome                                                                    WDL = 2500 mm                                           width of top of containing dome                                                                     WDH = 1800 mm                                           (hereinbefore referred to FIG. 5)                                             height of supporting insulator for                                                                  HG = 500 mm                                             insulation                                                                    height of cable head for conduction                                                                 HC = 430 mm                                             height of front part of collector head                                                              TA = 130 mm                                             length of current collector head in the                                                             LA = 600 mm                                             running direction                                                             distance between top of cable head for                                                              TB = 290 mm                                             conduction and trolley wire                                                   (hereinbefore referred to FIG. 7)                                             ______________________________________                                    

Room sufficient to contain the driving cylinder 32, the connector 6, thecylinder for raising and flatting 7 and so on can be obtained when themovable stroke of the driving cylinder 32 is approximately 300 mm.

The assembling procedure will be described next. The current collector20, composed of the collector head 22 and the driving cylinder 32,having the supporting insulator 30, the cylinder 7 for raising andlowering the current collector, the high voltage flexible cable 44 andthe connector 6, are mounted on the base plate 3o The current collector20 is in the condition where it is housed in the containing dome 4 (FIG.14). At this time, the driving rod 31 is withdrawn into the cylinder 7,reducing its length. The top of the collector head 22 is set on a bufferbase (not shown in the figure) installed on the base plate 3. Then, thecylinders 42, 129, 139, and 149 are secured to the base plate 3.

The assembled apparatus is mounted on the roof of the vehicle 2 and thebase plate 3 is fixed to the roof with bolts. In this condition, thecurrent collector 20 is in the housed condition. In this condition, thecylinders 42, 129, 139, and 149 may be also set in.

Next, the connector 6 and the cable 5 are connected. And, pipes fordriving liquid are connected to each of the cylinders 7, 32, 42, 129,139, and 149. The other work is to connect a signal wire to the sensor.

Then, the containing dome 4A is mounted on and fixed to the roof 2 withbolts. The shutters 110, 120, 130, and 140 have been attached to thecontaining dome 4A in advance. The cylinders 42, 129, 139, and 149 andthe shutters 110, 120, 130, and 140 are connected by access through theinspection hatches.

Next, the end portions of the containing dome 4B and 4C are mounted onthe roof and fixed to the roof 2 and the containing dome 4B. The portionconnecting the domes to each other is of an over-lapping structure.

The replacement of the high voltage flexible cable 44 or the cable head50 is carried out in such a manner that the containing dome 4 is removedin the condition where the current collector 20 is contained in thecontaining dome 4. The replacement work can be comparatively easilycarried out, since the opening 55a of the base 55 is directed upward andthe connector 6 is provided.

The cylinders 42, 129, and 139 may be horizontally installed in thecontaining dome 4B. When this is done, the dome 4 may be formed as aunit. Further, the inspection hatches may be miniaturized. The cylinders42, 129, and 139 may be easily connected with the shutters and thecontaining dome 4. This assembling is carried out with the containingdome 4 turned upside down.

The shutters 130 in the containing dome 4, where the sleeve 59penetrates, are also opened upward in an arc-shape. Each of the shutters130 has two semi-circular openings. And, two holes are formed withclosing of the two shutters 130. The sleeve 59 and the insulator 52penetrate these two holes. The holes have rubber buffers on theirperipheries. The hole for the sleeve 59 is slightly larger than theother, since the sleeve 59 moves upward and downward.

FIG. 21(a) through FIG. 21(c) show horizontal sectional views of thesupporting insulator 30 (30a, 30b, 30c) and the cable head 50, andrelationships between air flow and the configuration.

The FIG. 21(a) shows a combination where the round-shaped supportinsulator for insulation 30a has a slightly larger diameter than thediameter of the round-shaped cable head for conduction 50 (theaero-dynamic diameters are nearly the same), and they are placed in thestream. Although the air flow mainly hits the support insulator 30 whichis placed in front in the running direction, the air stream also hitsthe cable head 50 to produce noise in some cases.

The FIG. 21(b) shows a combination where the support insulator 30b has asignificantly larger diameter d1 than the diameter D1 of the cable head50. The air flow mainly hits the support insulator 30 which has a largediameter and is placed in front in the running direction, and the airdoes not hit the cable head 50. This results in a decrease in noisetotally.

    d.sub.1 >D.sub.1

d₁ and hatched part: concave portion of the insulator 30

D₁ outer diameter: convex portion of the cable head 50 insulator

The FIG. 21(c) shows a combination where the support insulator 30c isformed to have a wide width perpendicular to the air flow and a nearlystream-line shape, so that the cable head 50 is actively hidden withinthe protected area of the supporting insulator 30. When this is done,the noise decreases more than the case FIG. 21(b). It is desirable thatthe diameter or width of the supporting insulator 30 is, as describedabove, larger than the diameter of the cable head 50. Incidentally, thesupporting insulator 30 is made of epoxy resin.

The distance L between the two insulators 30 and 52 is determined fromthe low noise point of view. It is thought that interference of twonoises may lower the noise. Although the diameters of the supportinginsulator 30 and the cable head insulator 52 are the same size from thetop to the bottom (above the containing dome 4), the diameters may bevaried, for example, such as to increase in the downward direction. Whenthis is done, it is expected that the noise may be lowered since the airflow varies in the vertical direction.

Further, as shown in FIG. 22, it is desirable that the supportinginsulator 30 is placed just below the center of gravity G of thecollector head 22, that is the position on which the weight of saidcollector head 22 acts and the lift force L caused by the air flowhitting said collector head acts. A lift force L acts on said collectorhead 22 during vehicle running. When the vertical sectional shape ofsaid collector head 22 is symmetric with respect to a horizontal plane,the velocity in the downside thereof is lower than the velocity of theupside thereof since said supporting insulator 30 is installed.Therefore, the lift force acting in said collector head 22 acts upward.When the position of the lift force acting on the collector head 22 isat the position of the center of gravity G and said supporting insulator30 is installed at that position, the angular moment ML shown in thefigure is not caused. This means that no excessive force acts on thesupporting insulator 30.

It is desirable that the acting position of the center of gravity G ofsaid collector head 22 agrees with the acting position of the lift forceof said collector head 22. In a case where it is hard to cause saidposition of the center of gravity G to correspond with the actingposition of the lift force, it is desirable to make them as close aspossible.

It is thought that the containing dome 4 may cause upward turning of theair flow. As a countermeasure against this problem, the collector head22 may be tilted so as to match the angle of the air flow, or thecollector head 22 may be moved to a place where there is no effect ofthe angle of air flow caused by the containing dome 4. Therein, it isdesirable that the angle and the movement of the collector head 22 areadjusted corresponding to the speed of the vehicle.

FIG. 23 shows an application to a train of vehicles of the presentinvention.

In this figure, the vehicles 2 (2A-2H) are running from the right handside to the left hand side as shown with an allow. Generally, currentcollection is carried out with a vehicle in the rear of the train inorder to decrease the aero-dynamic resistance and to lower noise byplacing the current collector 20 in a place where a boundary layer morereadily develops. Therefore, in the figure, the two current collectors(20F, 20H) in the rear are raised, and the two current collectors (20A,20C) in the front are housed in the containing domes 4.

The electricity collected with the current collector 20 is directed to ahigh voltage unit box 60 through a high voltage connector 6 and a highvoltage cable 5. In this high voltage unit box 60, there are installed avacuum circuit breaker 61 and a vacuum circuit breaker 62 which areconnected with a cable head for current conduction 68 and a high voltagetake-out cable 67, respectively. The vacuum circuit breaker 61 preventsthe lowered and housed current collector 20, which is out of use, fromapplying high voltage with other current collectors 20 through the highvoltage take-out cable 67.

The vacuum circuit breaker 62 switches on and off current to currentcollector 20 installed in each vehicle. The current passed through thevacuum circuit breaker 62 in such a way is dropped in voltage with amain transformer 63, then the current is converted with a main convertor64 into three phase alternating current having its frequency and voltagecontrolled corresponding to the speed and the traction force of thevehicle to drive a main motor 65. The current, after driving the mainmotor 65, returns to a rail 69 through a wheel and axle 66. A highvoltage switch 61 cuts off high voltage from the current collector 20 atthe time when the current collector 20 is housed.

FIG. 24 shows an example of the arrangement of units in the high voltageunit box 60. There are installed two vacuum circuit breakers 61 and 62and four cable heads 68 in one box 60. Although the inside of the highvoltage unit box is at atmospheric pressure, the box is sealed. Thevacuum circuit breaker 61 and the vacuum circuit breaker 62 areinstalled in the top and the bottom of the box 60. Bare wires 68a areused for connections among both of the vacuum circuit breakers 61, 62and the insulators 68 for take-out conductors 68aa, 68ab, 68ac, 68ad.The vacuum circuit breakers 61 and 62, as known in the art, switch onand off the current in response to magnetic coils 61a and 62a. A cable68aa is used for connecting to the high voltage flexible cable 44, acable 68ab being used for connecting to the main transformer 63, cables68ac and 68ad being used for connecting to the other unit boxes 60. Thenumeral 68A indicates an arrester which is connected to the vacuumcircuit breaker 62. The vacuum circuit breakers 61 and 62 have the samespecification. Since the vacuum circuit breaker 61 is installed underthe floor of the vehicle, the center of gravity of the vehicle can belowered as compared to when it is installed on the roof. Further, thetwo vacuum circuit breakers 61 and 62 are installed in one unit box 60,which also leads to a lowering of cost.

Each vehicle in a train of vehicles has a control unit 84 having thefollowing structure as shown in FIG. 25. Since the train has fourcurrent collectors 20 (20A, 20C, 20F, 20H), the control unit 84 controlsfour sets. A set is composed of one vacuum circuit breaker 61, onedriving cylinder 32, two cylinders 7 for raising and lowering thecurrent collector, and six cylinders 42, 129, 139, and 149.

There are two sets of input switches SW, each of which is installed ineach of the driving cabs on both end vehicles of the train. The one setof switches SW is composed of a switch 9D1 to instruct which vehicle inthe train is the front vehicle, a switch 9D2 to raise all of the currentcollectors 20, a switch 9D3 to lower and house all of the currentcollectors 20 into the containing domes. The control unit 84 includes amemory 84A, a CPU 84B, and an input/output interface 84C.

The CPU 84B executes a program stored in the memory 84A, and executesvarious kinds of processing. When the switch 9D1 for instructing whichvehicle in the train is the front vehicle is switched on, the CPU 84B,as shown in FIG. 26, outputs a lowering command (262) to the two currentcollectors (20A, 20C) in the front side of the train and sends a raisingcommand (264) to the two current collectors (20F, 20H) in the rear side.

The operating procedure according to said lowering command is as shownin FIG. 27. In the condition in FIG. 4, the vacuum circuit breaker 61 iscut off (271) to prevent sparking. Next, the driving rod 31 is loweredup to the lowermost position to realize the condition in FIG. 18 (272).And, the shutters 110, 120, and 130 are opened by using the cylinders42, 129, and 139 (273). Next, the current collector 20 is housed in thecontaining dome 4 using the cylinder 7 as shown in FIG. 19 (274). Then,the shutters 110, 120, and 140 are closed by using the cylinders 42,129, and 149 (275). Therein, since the shutters 120 are overlapped, theoperation timings of the cylinders 129 are different from each other.

The current collector 20 is capable of being lowered with a small power,since the current collector 20 is first lowered with the driving rod 31to be detached from the trolley wire 1. Further, lowering the currentcollector 20 makes the length of the shutters 120 short and also makesthe length of the containing dome 4 short.

In the condition of lowering and housing the current collector 20, sincethe two openings on the shutter 130 (holes for the sleeve 59 and for theinsulator 52) are closed with the shutter 140, it can be expected tolower the noise during running. Further, the inflow of rain or snow canbe minimized.

When a rising command for the current collector 20 is given in the step264 in FIG. 26, as shown in FIG. 28, the shutters 110, 120, and 140 areopened (281), and the current collector 20 is raised (282), and then theshutters 110, 120, and 130 are closed (283). Next, the collector head 22is raised using the driving rod 31 to contact the trolley wire 1 (284).Finally, the vacuum circuit breaker 61 is switched on (285). The effectsare the same as described above.

A link mechanism may be installed between the insulator 30 and thedriving cylinder 32 instead of using the driving rod 31 to move theinsulator 30 upward and downward directly. When this is done, thedriving cylinder 32 may be used also in place of the cylinder 7 forraising and lowering the current collector 20.

FIG. 29 through FIG. 31 show a structure of the collector head drivingsystem 230 for vertical displacement control of the current collector20. A load cell for control 33 and a displacement meter 34 are insertedbetween the supporting insulator 30 and the driving rod 31. The outputsfrom the load cell 33 and the displacement meter 34 are lead to acontrol unit 83 together with the output information from a speedinformation detector 85 and a railway information detector 86, and thecontrol unit 83 calculates the optimum contact pressure against thetrolley wire 1 and transfers an electric signal to a servo amplifier ina servo control device 240. A servo valve 243 receives the electricsignal from the servo amplifier 242 and controls the liquid flow from aoil-hydraulic source 241 with the electric signal to control thepushing-up force u between the driving cylinder 32 and the driving rod31.

The following symbols are used in the description below.

f*: target contact force

fq: lift force

f: contact force

fx: fluctuating force signal

f : contact force estimated signal

fa : disturbance suppressing force estimated signal

P: estimating state value vector

A: matrix constant

L : vector constant

C: vector constant

B: vector constant

r: control signal=k₂ (f*-f )-fa

u: pushing-up force

k₁ ': disturbance compensating gain

k₁ ": contact force gain

k₂ : normal compensating gain

a₁ -a₈ : weight functions (forming k₁ ')

a: equivalent mass of the trolley wire 1

b: equivalent damping coefficient of the trolley wire 1

m₁ : mass of the contact strip 21

m₃ : mass of the collector head 22 and the supporting insulator forinsulation 30

Y₁,Y₁ ',Y₁ ": vertical displacement, vertical velocity, verticalacceleration of the contact strip 21

Y₃,Y₃ ',Y₃ ": vertical displacement, vertical velocity, verticalacceleration of the collector head 22 and the supporting insulator forinsulation 30

z,z',z",z'": displacement, velocity, acceleration, acceleration ratio ofthe irregularities of the trolley wire 1

c₁ : damping coefficient of the spring 23 for pus] the contact strip

k₁ : spring constant of the spring 23 for pushing the contact strip

ζ: ratio of damping coefficient

X: state value vector

W: disturbance vector

D, E: vector constants

H: vector constant

Q: output state value vector from the normal difference compensatingunit 232

F: scalar constant

G: vector constant

The servo control device 240 operates the driving cylinder 32 and thedriving rod 31 with a control signal r from a control unit 83 to producea push-up force u to the collector head 22, the support insulator 30 andso on. The control unit 83 is installed on the earth side (electricpotential is zero) in the collector head containing dome 4 in the roofof the vehicle 2. The control unit 83 inputs a fluctuating force signalfx and a vertical displacement signal y₃ to a contact force observerunit 233. The signals are obtained through amplifying the output signalsfrom a load cell 33 and a displacement meter 34 which are installedbetween the support insulator 30 and the driving rod 31, using adetected signal checking circuit 253. Further, the control signal r isfed at the same time to the contact force observer unit 233. Then, thecontact force observer unit 233 outputs with estimation a contact forceestimated signal f and a disturbance suppressing force estimated signalfa . The contact force observer unit 233 is composed of a state valueestimating unit 236, a disturbance suppressing force gain unit 237 and acontact force estimating unit 238.

Furthermore, the control unit 83 has a target value command unit 231,which sets with optimizing and varying a contact pressure target valuef* by means of the combination of information signal on running placeand a detected signal on running speed, using the running information(speed information 85, route information 86) from the controller on thevehicle, and a normal difference compensating unit 232, which calculatessaid control signal r [=k2 (f*-f )-fa ] through obtaining differencesbetween the contact pressure target value f* set by the target valuecommand unit 231 and the contact force estimated signal f output withestimation by the contact force observer unit 233 or the disturbancesuppressing force estimated signal fa .

Herein, k₂ is a normal compensating gain in the normal differencecompensating unit 232. The load cell 33 is installed between the supportinsulator 30 and the driving rod 31, and detects the load, eithertension of compression, with high accuracy to output a fluctuating forcesignal fx.

Similarly, the displacement meter 34 is installed between the supportinginsulator 30 and the driving cylinder 32, and outputs the verticaldisplacement, the velocity and acceleration of the driving rod 31. Thelift force mainly acts on the collector head 22, the supportinginsulator 30 and so on, and consists of the resultant lift force fq ofaverage lift force and fluctuating lift force acting vertically.Therefore, when the vehicle runs at a high speed, the fq acting on thetotal body of the current collector 20 increases, and accordingly thecontact pressure f substantially varies.

Said contact pressure is expressed with an equation (Equation 1).

    f=fx -m.sub.1 Y.sub.1 "-m.sub.3 y.sub.3 "-fq               (Equation 1)

wherein, the y₁, y₁ ', y₁ " are the displacement, velocity and theacceleration of the current collector contact strip 21 and so on. TheY₃, Y₃ ', Y₃ " are the displacement, the velocity and the accelerationof the collector head 22, the supporting insulator for insulation 30 andso on.

The target value command unit 231 sets with optimizing and varying thecontact pressure target value f* by using the running information(running speed, running route, position, weather, running time,earthquake etc.) transferred from a vehicle controller. The normaldifference compensating unit 232 receives an input signal whichsubtracts the contact force estimated signal f from the f* set by thetarget value command unit 231, and outputs the signal Q [=k2 (f*-f )]which is obtained through multiplying the compensating gain k₂ and thesignal ef. The control signal r, which is obtained by subtracting thedisturbance lift pressure estimated signal fa from Q through asubtractor, is input to the servo control device 240. The driving rod 31is operated using the control signal r so as to suppress the lift forcefq and the external force from the trolley wire 1.

In order to calculate the disturbance suppressing force estimated signalfa , the disturbance suppressing force gain unit 237 multiplies thefollowing weight functions of the disturbance compensating gains k₁ '(a₁ -a₈) to the output signals (y₁, y₃, y'₁, y'₃, z, z', z", z'") fromthe state value estimating unit 236, which contains the lift force fqand the external force from the trolley wire 1. Wherein, z, z', z", z'"are the displacement, the velocity, the acceleration and theacceleration ratio of the convex and concave of the trolley wire 1.

    a.sub.1 =268,500, a.sub.2 =-268,500, a.sub.3 =-28,650, a.sub.4 =-1,212, a.sub.5 =0, a.sub.6 =29,850, a.sub.7 =45, a.sub.8 =0.

Then, fa can be obtained.

    fa =k.sub.1 'xP                                            (Equation 2)

The contact force estimating unit 238 calculate s the contact forceestimated signal f (the equation (Equation 3)) using the output signalsP (y₁, y₃, y'₁, y'₃, z, z', z", z'") from the state value estimatingunit 236. Wherein, a is an equivalent mass of the trolley wire 1, and bis an equivalent damping factor of the trolley wire 1. ##EQU1##

This equation can be expressed as follows,

    f =k.sub.1 "xP                                             (Equation 3)

Therein, k₁ is the spring constant of the pushing spring 23 for thecontact strip, c₁ is the damping coefficient of the pushing spring 23for the contact strip, and k₁ " is the contact force gain.

The signal P described above will be explained next. After judgingwhether or not the output signals detected with the load cell 33 and thedisplacement meter 34 are normal, using the detected signal checkingcircuit 253, the varying signal fx and the vertical displacement Y₃together with said control signal r is input to the state valueestimating unit 236, and then the unit 236 outputs the eight statevalues described above, Y₁, Y₃, Y'₁, y'₃, z, z', z", z'", through stateestimating by means of the minimum dimension observer method. Thecalculation to obtain the state values using the minimum dimensionobserver method (Gopinath's method) is described in the book titled"Observer" published from Corona Co. (1988) page parts 21-32. Theequations of state (Equation 4) are shown below.

    d/dt(P)=(A-L C)xP+BxU+L xF.sub.x                           (Equation 4)

Wherein, the P is an estimated state value of observer (y₁ , y₃ , y'1₁ ,y'₃ , z , z' , z" , z'" ), the F_(x) being an input scalar to the forcedetector, the A being an 8×8 matrix, the L being a 1×8 vector, the Cbeing a 1×8 vector, the B being a 8×1 vector. Therefore, since the eightcharacteristic roots of the collector 20 are on the points (-0.128,j±12.34), (-1.212, j±121.84), (-1.88, jO), (-23.69, jO), (-27.67,±j98.19) in the complex coordinate, the seven observer characteristicroots of the state s estimating unit 236 are determined on the complexcoordinate in such a manner as follows. That is to determine the rootsof the matrix (A-L C) in the equation (Equation 4).

    (-6.0, ±j12.34), (-23.69, j+0), (-27.67, ±j98.19), (-60, j±121.84)

As can be understood from these points, the roots, (-6.0, ±j12.34) and(-60, j±121.84), are determined such that the damping characteristicsfor the two roots depending on the disturbance, (-0.128, j±121.84) and(1.212, j±121.84), are improved (ζ=0.01 →0.44).

A method for active control of the disturbance suppression force usingthe contact force observer unit 233 will be described next. The equationof the state for the collector 20 including the external force of thetrolley wire 1, the lift force and so on is expressed as follows:

    d/dt(X)=AxX+BxU+DxW                                        (Equation 5)

    f=CxX+ExW                                                  (Equation 6)

Wherein, X is a state value y₁, y₃, Y'₁, y'₃, z, z', z", z'") vector,the pushing-up force vector u=H×R, r being a control signal vector, Hbeing a vector constant, f being an output scalar for the contact force,W being an input scalar of the disturbance, A being an 8×8 matrix, Bbeing an 8×1 vector, C being a 1×8 vector, D being an 8×1 vector, Ebeing a 1×8 vector.

And, the equation of state for the normal difference compensating unit232 is expressed as follows.

    d/dt (Q)=FxQ+G(f*-f )

Then, the following equation can be obtained.

    Q=k.sub.2 (f*-f )                                          (Equation 7)

Wherein, k₂ is the normal compensating gain vector, Q is an output statevalue (1×1) vector of the normal difference compensating unit 232, Fbeing a scalar constant, G being a vector constant, (f*-f ) being aninput scalar to the force difference value control signal. ##EQU2##

Therein, k₁ ' and K₂ are vector constants, and there are therelationships K₁ =-Hxk₁ ' and K₂ =H. From Equation 5-Equation 8, all theequations of state for the optimum contact pressure target value f, andthe contact pressure f and the push-up force u are expressed as follows.##EQU3##

Thus, using Equation 7 through Equation 10, the contact force can bedecreased by inputting said control signal r for the pushing-up force u(Equation 8) based on fa and f to the servo control device 240, faz andf are obtained through inputting said control signal of the varyingforce signal fx and the push-up force u to the contact force observerunit 233. The disturbing compensating gain k₁ ', the vector constant Hand the compensating vector F/G used at this time are required to beselected properly.

FIG. 31 shows a structure of the current collector driving system 244which receives said control signal r to output the pushing-up force u.The system 244 is composed of an amplifying circuit 242 to amplify saidcontrol signal r, a servo valve 243 to control the oil pressure from anoil-hydraulic pressure source 241, a driving cylinder 32 and a drivingrod 31 to produce the pushing-up force u by the action of expansion andcontraction-caused by the servo valve 243.

Although an oil-hydraulic pressure source 241 is used in this example, acompressed air source may be used, as described later, when the responseof the servo valve and cylinder is fast enough. In this case, thetransfer characteristic of the pushing-up force u corresponding to saidcontrol signal r is required to be of the same order.

FIG. 32 is a block diagram showing the operation of the two containingsystems 360a and 360b to lower and house the collector head 22 in thecontaining dome 4, wherein the two rods for raising and lowering 8a and8b are operated to expand and contract and the collector 20 is operatedto rotate through the rotating system 40. The two containing systems360a and 360b are composed of amplifiers 361a and 361b. switching valves362a and 362b, cylinders for raising and lowering 7a and 7b. When thecontaining systems receive the operation signal from the controller forraising and lowering 364 installed in the containing dome 4, thecontaining systems are operated with oil-hydraulic pressure from theoil-hydraulic pressure source 363 to raise the current collector 20perpendicular to the car body 2 with the rods 8a and 8b, as shown inFIG. 18, so as to collect current from the trolley wire 1. On the otherhand, when the current collector 20 is to be lowered, the containingsystem disconnects the contact strip from the trolley wire 1 and lowersit into the containing dome 4 using the projecting rods 8a and 8b, asshown in FIG. 19.

Another embodiment of the present invention may be realized with use ofmotors for driving the current collector 20 instead of oil-hydraulicpressure.

For a comparatively low running speed vehicle, the shutter system forthe containing dome 4 is not required. Since the containing dome 4itself has a substantial effect to decrease noise, the opening, throughwhich the current collector 20 is put out or into, may be kept open.

FIG. 33 shows a further embodiment of the present invention where a highvoltage flexible cable 44 for current conducting is held in the hollowportion of the supporting insulator 30. A conductor 53 is installed inthe inside of the insulator to support a collector head 22. In otherwords, a cable head for current conduction supports the collector head22. The high voltage flexible cable 44 is drawn out of the side of theinsulator 30. The collector head 22 is fixed with a nut and a screwwhich is formed on the top end of the current conductor in the cablehead 22. Therewith, there is an advantage in that a structure havingonly one insulator can be realized.

However, it is undesirable for the life of the high voltage flexiblecable 44, since the high voltage flexible cable 44 moves upward anddownward accompanied with the operation of the driving rod 31.

FIG. 34 shows another embodiment of the present invention which isapplied to a current collecting system of a third rail type.

In this embodiment, the present invention is applied to a vehicle whichcollects current from a third rail installed on the side of the rail-wayinstead of current collecting from a trolley wire installed above thevehicle.

The current collecting of this type is widely used for a subway vehicle,wherein the positive voltage is applied to the third rail 76 installedon the side of the rail-way to miniaturize the tunnel cross section, anda negative voltage is applied to the rails 75 on which the vehicle runs.The third rail 76 is insulated with insulators 77. Current collecting isperformed by pushing a current collecting shoe 73 against the third rail76.

There is an insulator 72 on the vehicle side of the current collectingshoe 73 to insulate the high voltage from the vehicle, and there is anoil-hydraulic cylinder 71 on the further vehicle side to control thepushing force for the current collecting shoe 73. The oil-hydrauliccylinder 71 is fixed to an axle box body or a bogie frame 70 havingsmall displacement with respect to the rails 75. The (Equation 7)electricity collected by the current collecting shoe 73 is transferredto a cable head 78 through a flexible conductor 74 and then is suppliedto a control system installed on the vehicle 2.

FIG. 35-FIG. 37 show a further embodiment of the present invention. Inthis embodiment, the current collector 20 is rotatably flatted rearwardwith respect to the running direction. There are cylinders 7 and aconnector 6 on the front side position in the running directionindicated with an allow. A high voltage flexible cable 44 is positionedbetween the branches of a hinge supporting the current collector 20. Thedomes 4A, 4B, 4C are inversely positioned in the running direction withrespect to the embodiments described above.

Therein, when the current collector 20 is housed in the containing dome4, the vertex of a triangle of the collector head 22 comes to the upperside. Therefore, the size of the containing dome 4 can be miniaturizedas compared to the embodiments described above, which decreases therunning resistance. This can be easily seen from a comparison of FIG. 37with FIG. 5, for example.

Although the supporting insulator 30 is kept standing upright duringrunning in the above embodiments, it is possible that the tilting angleof the support insulator 30 may be varied corresponding to the runningspeed by operation of the cylinders 7 for raising and lowering thecurrent collector to control the wing force. In this case, it isdesirable that the current collector contact strip 21 and the collectorhead 22 are formed to be arc-shaped. Further, when the wind from thecontaining dome strongly affects the current collector 20, it isdesirable to move the current collector 20 toward the running direction.

Since the lift force acts on the collector head 22 during high speedrunning, the collector head 22 is controlled such that the top front ofthe collector head 22 is directed slightly downward using the cylinder7. In FIG. 32, the controller for raising and lowering 364 operates thecylinder 7 such that the top front of the collector head 22 is directedslightly downward when the vehicle runs faster than a given runningspeed using the running speed information from a controller on thevehicle. And, the command from a central operation room is also used.

Since the lift force becomes large when the vehicle is passed by anothervehicle in a tunnel, the collector head 22 is similarly directeddownward. When the vehicle enters into a tunnel at a high speed, thecollector head 22 is also directed downward. In FIG. 32, the controllerfor raising and lowering 364 operates the cylinder 7 using the runningposition information from the controller on the vehicle or the commandfrom the central operation room.

Furthermore, a baffle plate may be placed at the back of the cable head50 to straighten the air flow downstream of the cable head 50. Thebaffle plate is preferably made of an insulating material and attachedto the mounting base 55 for the cable head 50.

It is desirable to provide an emergency ground switch EGS in the currentcollector 20. That is, as shown in FIG. 39, an emergency ground switchEGS 300 is installed parallel to the cable head 50 in the currentcollector 20. The emergency ground switch EGS has a copper rod 303driven by a cylinder mechanism 302 operated by a compressed air source301. The copper rod 303, which is normally in the containing dome, isprojected from the containing dome in response to a driver's emergencyoperation to connect its upper end to the collector head 22 through aclip 304, as shown in the figure. The numeral 305 indicates a braidedcopper wire connected to the base plate 3. The emergency ground switchEGS has the function on to shunt the vicinity of the collector head 22to the ground as fast as possible in an emergency. The emergency groundswitch EGS cylinder mechanism 302, which is formed with the cylinder 32as a unit, is rotated to be raised or lowered together with thesupporting insulator 30 and the cable head 50 by the rotating system 40.

In accordance with the present invention, it is possible for the cablehead 50 for current conduction to be installed with a mechanism allowingit to tilt to make the high voltage cable easily movable. When this isdone, the cable head 50 for current conduction is not parallel to thesupport insulator 30, which decreases the standing wave produced betweenthem and thus further decreases noise.

According to the embodiments of the present invention described above, apart of the structure having a current collecting function can be lightin weight and small in size and can improve the control characteristicto follow the trolley wire 1, since the part of the structure having thecurrent collecting function, which comprises the current collectingmember and the driving system, is installed separately from the part ofthe structure having the power current conducting function, which can,further, maintain the power current collecting function sufficiently.

Furthermore, the generation of noise during vehicle running can besuppressed, since there is provided a containing system on the roof ofthe vehicle inside of which the driving system is always contained andin which the part of the structure having the current collectingfunction together with the part of the structure having the powercurrent conducting function is contained when it is not needed.

Referring to FIG. 40 through FIG. 51, various features of the currentcollector 20 and its performance will be discussed. In FIG. 40, thecurrent collector 20 comprises a current collecting contact strip 21 tocollect current from a trolley wire 1, a collector head 22 having afront portion in the running direction which is swept back in itslongitudinal direction to mount the current collecting contact strips21, a supporting column 400 having a stream-line shape to support thecollector head 22, an insulator 500 to insulate electrically the vehiclebody 2 from the current collector 20 and driving means (not shown) fordriving them vertically.

Since the contact strips 21 and the collector head 22 of conventionalcurrent collectors 20 are formed of two dimensional shaped members, suchas circular bars, a two dimensional vortex typical of a Karman vortex iseasily generated and so a large aero-hydraulic noise and a large airresistance is also generated, which has been a problem for high speedrunning. Since the stream-line shaped current collector proposed todissolve this problem suppresses generation of a Karman vortex ascompared to the non-stream-line shaped current collector, the noise canbe lowered. However, since the current collector 20 has, even in thiscase, long members in the direction perpendicular to the runningdirection, the flow is apt to become two-dimensional. Therefore, evenwhen the collector head is formed in a stream-line shape, the degree ofgenerating aerodynamic noise has been large.

Although the noise for the stream-line shaped current collector 20 islower the that for the non-stream-line shaped current collector 20, afurther low noise current collector 20 has been desired for low noisehigh speed running.

Since the current collector 20 according to the present inventionprovides a collector head 22 having a front portion in the runningdirection which is swept back in its longitudinal direction,longitudinal vortexes are generated around the collector head 22. Thelongitudinal vortexes suppress generation of a vortex having a twodimensional structure typical of a Karman vortex. FIG. 41 and FIG. 42illustratively show the flow around collector heads, a collector head305 (FIG. 41) according to the present invention and a wing-shapedcollector head 306 (F,G.42) used in a general stream-line shaped currentcollector 20. In the current collector 305 according to the presentinvention, the longitudinal vortexes suppress the vortexes withsynchronized phase which are apt to generate noise, and consequentlysuppress generation of noise.

FIG. 43(a) through FIG. 44(b) illustratively show pressure distributionon the surfaces of collector heads. In the conventional two dimensionalwing 308, as shown in FIG. 44(a), since the wake is two dimensional, thepressure on the surface is also uniform and two dimensional along thelongitudinal direction of the wing 308, as seen in FIG. 44(b). On theother hand, in the collector head 307 having a sweep-back front endsurface according to the present invention, as shown in FIG. 43(a),since the pressure distribution is not uniform along the lateraldirection of the collector head 22, as seen in FIG. 43(b), the noise ishardly generated.

In order to lower the aerodynamic noise generated by the flow around theconnecting portion between the collector head 22 and the supportingcolumn 400, the connecting portion between the collector head 22 and thesupporting column 400 is formed with a curved surface, as shown in FIG.45. Stated in another way, the connecting portion is formed with apolygon surface such that the connecting portion has no acute angle.When the connecting portion between the collector head 22 and thesupporting column 400 has an acute angle or a right angle, there appearsa secondary flow there to generate aerodynamic noise. Since an abruptchange of flow in the vicinity of a wall surface is apt to generatenoise, employing the connecting portion according to the presentinvention decreases noise. Especially, when the length S₂ of the portionwhere the smooth surface contacts the collector head 22 is nearly onethird of the length S₁ of the collector head 22 in its longitudinaldirection and the length S₃ between the bottom surface of the collectorhead 22 and the portion where the smooth surface contacts the supportingcolumn 400 is nearly one sixth of the length S₁ of the collector head 22in its longitudinal direction, the effect to lower the noise is large.

FIG. 46 shows the result on noise obtained from a wind tunnel test usinga model of a current collector 20 according to the present invention, aswell as showing the result of a conventional current collector 20 forcomparison. The current collector 20 according to the present invention(circles) lowers the noise by approximately 20 dB compared to theconventional current collector, and by more than 5 dB compared to thestreamline shaped current collector.

It is also preferable that the collector head 22 has a shape where thecross section of the collector head is wing-shaped and the front faceson both sides of the collector head are swept back. For the collectorhead 22 having such a shape as described above, since the edges areswept back to the collector head, the contact strip 21 on the edge linewill not generate vortexes which are uniform and have synchronizedphase, and consequently the noise is lowered.

In FIG. 47, collector head 22 has the shape of a rhombus (in plan view)formed by combining two collector heads having front faces on both outersides 22A swept back against the central portion 22B fore and aft. Thatis, the collector head is symmetrical in the fore and aft directions andhas a shape where the front edges are swept back in the longitudinaldirection from the center of the collector head, which realizes a lownoise current collector 20 generating a longitudinal vortex which issymmetrical fore and aft.

The both side ends of the collector head 22 are formed in convex curvedsurfaces on the upper surface side contacting the trolley wire 1 so asto minimize generation of wing top vortexes and so as to guidecrossover.

There is a further aspect of the present invention in which theeffective length of the contact strips 21 are changed depending on lowor high speed running and corresponding to the running direction. Duringa low speed running, the effective length of the contact strip 21 islong to cope with a trolley wire change and the like. 0n the other hand,during high speed running, the shape of the collector head 22 changesinto a shape suitable for decreasing noise.

There is another aspect of the present invention wherein a turntable isinstalled to mount a current collector 22 and rotate the currentcollector 22 corresponding to the running direction of the vehicle. Byemploying this technology, the number of the current collectors 20 to bemounted on the train can be decreased.

FIG. 48 shows another form of the current collector 20 in which thecollector head 22 has its maximum vertical thickness (h_(max)) positionP of the wing shaped cross section located more than 30 percent of thechord length (C) from the front edge of the wing-shape, and the uppersurface of the collector head 22 in the vicinity of the rear edge is aconcave curved surface. In the case where the collector head 22 has sucha shape as described above, it has been confirmed that the pressure dropfrom the maximum pressure point to the rear end is gentle and theaerodynamic noise is decreased. Therefore, the collector head 22 havingthis cross sectional shape according to the present invention iseffective to decrease noise. Further, the collector head having asymmetrical shape to the horizontal line has had a high effect.

FIG. 49 shows a further form of the current collector with a supportcolumn 400 for the collector head 22 having a shape of a circular coneor elliptic cone 400a, which hardly will cause aerodynamic noise.Therewith, the flow around the supporting column varies in the verticaldirection to make the flow three dimensional and to suppress thegeneration of noise.

FIG. 50 shows another form of the current collector of the presentinvention. When the contact strip 21 is of a two-dimensional shape, alarge aerodynamic noise is generated. In this case, at least one or moreprojections 222 having a long shape in the running direction of thevehicle are provided at the positions narrower than the contact strip 21in the vicinity of the front edge forward of the contact strip 21 on thecollector head 22, and longitudinal vortexes are generated with theseprojections to suppress the Karman vortex-like aerodynamic noise causedby the contact strip 21. Especially, when more than three of theprojections 222 are attached to the width of the contact strip 21, theeffect to decrease noise is large.

FIG. 51 shows a result of a wind tunnel test for studying the noisedecreasing effect of the present invention. The projections 222 forgenerating a longitudinal vortex according to the present invention iseffective for decreasing noise.

According to the present invention, it is possible to decreaseaerodynamic noise in a current collector for a high speed railwayvehicle by using a collector head having a swept-back shape in itslongitudinal direction so as to actively generate longitudinal vortexeson the collector head to suppress generation or the two dimensionalvortex having a synchronized phase, that is to say, a vortex which isapt to generate aerodynamic noise, such as generated in a conventionalcurrent collector. Further, it is possible to decrease the aerodynamicnoise produced from the connecting portion between a collector head anda supporting column by not only forming the collector head and thesupporting column in stream-line shapes, but also smoothly connectingthe collector head and the supporting column so as to suppressgeneration of a secondary flow at the connecting portion of thecollector head and the column so as not to interfere with thelongitudinal vortexes generated by the collector head.

According to another feature of the present invention, it is possible todecrease the aerodynamic noise caused by a two dimensional flow producedby the current collector by generating a three dimensional flow using aduct to generate a swirl flow.

According to a further feature of the present invention, parts of thecollector head are movable so as to provide a function to guide thecrossover of the trolley wire during low speed running and to provide ashape for low aerodynamic noise by flatting the collector head to lowernoise during high speed running. With the structure, it is possible toobtain a shape which is low in noise generation during high speedrunning with no problem in changing the trolley wire during low speedrunning.

We claim:
 1. A current collector for a railway vehicle comprising acurrent collecting member having a collector head, a driving system formoving said current collecting member into and out of contact with acurrent source, and a conductive element for conducting electric powercollected by said current collecting member to a load, wherein saidcollector head has a substantially triangular wing shape, with the frontedge of said collector head swept back from the center thereof to outeredges thereof, and with the top surface of said collector headdownwardly swept back.
 2. A train comprising a plurality of railwayvehicles, each of four of said railway vehicles having a currentcollector, each current collector including a collector head mounting acurrent collecting member thereon, a driving system for moving saidcollector head into and out of contact with a current supplying body tocollect current, and an electric conducting system installed betweensaid collector head and the associated vehicle body; each of saidcollector heads having a wing shape; two of said railway vehicles withcurrent collectors being mounted between the lengthwise center of saidtrain and one end of said train and being mounted with the fronts ofsaid collector heads toward the lengthwise center of the train, and theother two of said railway vehicles with current collectors being mountedbetween the lengthwise center of said train and the other end of saidtrain and being mounted with the fronts of said collector heads towardthe lengthwise center of the train.
 3. A method of collecting current ona train having a plurality of vehicles, each of four of the vehicleshaving a current collector thereon, each of said current collectorsincluding a collector head mounting a current collecting member, adriving system for moving said collector head into and out of contactwith a current supplying body to collect current, and an electricconducting system for conducting current from said collector head to thevehicle, the front of each collection head being directed toward thelengthwise center of the train, said method comprising the stepsof:driving the two of said current collectors mounted to the rear ofsaid train in the running direction into contact with said currentsupplying body, and driving the two of said current collectors mountedto the front of said train in the running direction out of contact withsaid current supplying body.